Amyloid deposits are one of the hallmark pathological lesions of Alzheimer\'s disease (AD).They can be visualized by thioflavin-S,silver impregnation,Congo red staining,and immunohistochemical reactions.However,that amyloid deposits generate blue autofluorescence (auto-F) has been ignored.Here,we report that visible light-induced auto-F of senile plaques (SPs) was detected and validated with conventional methods.Brain slices from APP/PS 1 (amyloid precursor protein/presenilin 1) transgenic mice were mounted on slides,rinsed,coverslipped and observed for details of the imaging and spectral characteristics of the auto-F of SPs.Then the slices were treated with the above classic methods for comparative validation.We found that the SP auto-F was greatest under blue-violet excitation with a specific emission spectrum,and was much easier,more sensitive,and reliable than the classic methods.Because it does not damage slices,observation of auto-F can be combined with all post-staining techniques in slices and for brain-wide imaging in AD.